Halogen exchange reactions on chlorine-substituted species are known as a method for introducing the fluorine atom into aromatic monocyclic and condensed polycyclic hydrocarbons (scheme 1).

The synthesis of hexafluorobenzene and the synthesis of octafluoronaphthalene, which is useful as a starting material for organic dielectric film materials, by this method has been reported (See Non-patent documents 1 to 3.). A problem with this method, however, is the difficulty in obtaining the starting chlorine-substituted species.
A method has also been reported, as shown in scheme 2, in which a cyclic perfluorocompound is synthesized by a defluorination reaction mediated by reducing agent, such as a metal or the like. For example, hexafluorobenzene (See Non-patent document 4.), octafluoronaphthalene (See Non-patent documents 5 to 7.), and decafluoropyrene (See Non-patent document 8.) have been synthesized by this method. However, very severe reaction conditions, i.e., a reaction temperature of at least 400° C., are generally required when the starting material does not contain a carbon-carbon multiple bond.

When the starting material has at least one carbon-carbon multiple bond, the defluorination reaction proceeds under mild conditions using metal as the reducing agent. For example, as shown in scheme 3, decafluoroanthracene is obtained from 1,2,3,4,5,6,7,8,9,9,10,10-dodecafluoro-9,10-dihydroanthracene at a reaction temperature of 225-280° C. (See Non-patent document 9.). In addition, octafluoronaphthalene has been obtained by this method from 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8-hexadecafluoro-1,2,3,4,5,6,7,8-octahydronaphthalene (See Non-patent document 10.).

However, it is difficult to obtain fluorinated pentacene derivatives even by the heretofore known methods described above; for example, tetradecafluoropentacene has not been prepared. Moreover, no examples of the synthesis of partially fluorinated pentacene derivatives have been reported.                Non-patent document 1: J. Am. Chem. Soc., 1947, Volume 69, page 947        Non-patent document 2: Indust. Engng. Chem., 1947, Volume 39, page 393        Non-patent document 3: J. Am. Chem. Soc., 1943, Volume 65, page 2064        Non-patent document 4: J. Am. Chem. Soc., 1938, Volume 60, page 492        Non-patent document 5: Nature, 1959, Volume 183, page 588        Non-patent document 6: Science, 1996, Volume 271, page 340        Non-patent document 7: J. Org. Chem., 1992, Volume 57, page 2856        Non-patent document 8: Tetrahedron, 1963, Volume 19, page 1893        Non-patent document 9: Zh. Org. Khim., 1971, Volume 7, page 745        Non-patent document 10: J. Fluorine Chem., 1990, Volume 48, page 29        